Wheel-trimming machine



T. LARSSON.

WHEEL TRlMMlNG MACHINE. 'APPLlcAIloN FILEDJPR. 11, 1920.

1,377,991 Patented May10,1921.

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T. LARVSSON. WHEEL TRIMMmG MAcHzNr-I.

APPLICATION FILED APR. 17| 1929.

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T. LARSSON.

WHEEL TRIIMNIINGMACHINE. APPLICATION. man APRi 17, 1920.

Patented May 10,1921.

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F INVENTOR Thum Larsson @R'nesses www ucznm i UNITED STATES PATENT'QFFICE.

TE'URE LARSSON, OF WORCESTER, MASSACHUSETTS, yASSIGNOR TO NORTON COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION 0F MASSACHUSETTS.

. .WHEEL-TRIMMNG MACHINE.

Specification of Letters Patent.

Application "filed April 17, 1920. Serial No.- 374,575.

To al? whom t may concern.

Be it known that I, THURE LARssoN, a citizen of the United States of America, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in I/Vheel-Trimming Machines, of

which the following is a full, clear, and

exact specification.

My invention relates to a wheel trimming machine and more particularly to a device adapted for trimming the lead bushings of grinding wheels.

It is the practice in the grinding wheel art to cast a bushing of lead vor lead alloy around the hole in the wheel through which the spindle of the machine engages. To give the wheel a neat and finished appearance it is necessary to trim this bushing on lthe wheel side to make it flush with the latter. l-leretofore this trimming has been done manually by means of a Atrimming knife somewhat on the order of a chisel, or in some cases by clamping the wheel in a chuck,l

resulting, especially in the case of coarse' grained wheels, in an uneven and unfinished appearance of the trimmed bushing. The second method described involves a number of operations such as placing the wheel in the chuck, clamping the jaws on the wheel with a wrench, starting the rotation of the relatively heavy chuck, :feeding the cutting tool to the wheel and again stopping the chuck, these various operations taking considerable time and being, to a large extent, unsuited for rapid production work,v especially in the case of small and specially shaped wheels.

It is one object of my invention to overcome such objectionable features and construct a machine which is simple in design, highly efficient in operation and by the use of which I am enabled to increase production with'a minimum of' manual labor and expense. A

A further object of my invention 1s to provide a device of this type in which various' sized wheels may be rotated positively, 1 but without being 'clamped to the driver, by

to avoid the necessity for using a centering spindle or chuck Iand to correctly position a wheel relativeto a cutting tool for rotation about the wheel axis by swinging driving rollers inwardly to positions equidistant from said axis into engagement with the wheel periphery.

In addition to these objects, the inven..

tion is further designed to provide certain improvements for controlling the feedbf a cutting tool with relation to the wheel bushing with more accuracy than has hitherto been possible, and for otherwisel enhancing and increasing the efiicien'cy of de-l vices of this character.

To these and other ends, the invention consists in certain improvements and combination of parts, all as lwill hereinafter be more fully'described, the novel features being pointed out in the claims at the end of the specification.

Figure l is a cross'section'of the machine taken on the line 1'-1 of Fig. 2 and showing part of the cutting tool feeding mechanism in section to more clearly bring .outv

the details of thel construction;

Fig. 2 is a plan view .ofthe machine with a wheel placed thereon, part of the whee and casing being broken away;

Figs. 3, 4 and 5 are sections on the lines 3-344 and 5--5 respectively of Fig. 2, Fig. 3 showing a dust and gritexcluding plate which is, for simplicity of illustration, not shown in any-'of the other figures;

Fig. 6 is an elevation of the stop member for lthe cutting tool'support; and

Fig. 7 is a detail view showing the manner of mounting the .cuttingtool In accordance with my invention I provide a device particularly adapted for trimming wheels and particularly; the bushings of grinding wheels, in which.V the wheel is rotated, by means of a positively driven roller frietionally engaging the surface thereof, in engagement with. a cutting tool adjustably mounted relative thereto. The preferred embodiment of my invention comprises a preferably horizontal wheel supportor turntable lxadapted `to receive the wheel 2 being trimmed. To rotatefthe wheel I provide one or more positively driven vrollers 3' adapted to :frictionally: engage and Patented May 1o, 1921. i

drive against the wheel periphery 4. By using three of such rollers the wheel may be centered and for this purpose, as well as to accommodate different sized wheels, the rollers 3 are mounted on arms 5 (Figs. 2 and 3) to swing toward the wheel axis. Suitable mechanism, such as a train of gears, connects one or more of the rollers with a power shaft 6 to drive the same continuously. For trimming the bushingV 7 while the wheel is beine driven, I provide a cutting tool 8 (Fig. 1?), preferably of the well-known conical cup type used in dressing grinding wheels, mounted for adjustment at right angles to the wheel axis on av support or slide 9, which, in turn, is movable in a vertical direction. This-support is preferably operated by means of a hand wheel 10 connected therewith through a 'suitable drive which may comprise a rack 11 and a pinion 12 (Fig. 1.)

Proceeding now to a more detailed description of the device, I have shown the wheel support or turntable 1 rotatably mounted on a stud 13 by having a centrally disposed sleeve 15 on the support engaged over'the upper end of the said stud. To minimize the friction and take up the end thrust a ball 16 is placed within the sleeve 15 and on the. end of the stud 13. This sleeve 15 has a rotating fit in an opening 17 in a casing 18, the purpose of which will be described later on. The friction between thewheel side and the turntable causes the latter to rotate with the wheel.

The mechanism for driving and swinging the rollers 3 is mounted on a base 19 `and is, for the most part, covered by the casing 18, forming with the base a substantially inclosed chamber. Near the center of the base is fastened the short, upright stud 13, above referred to', having a colla-r 21 thereon between its'ends. Between this collai1 and an upwardly extending annular flange 22 on the base and surrounding the stud is rotatably mounted the gear 23 which forms part of the train of gears'for driving` the rollers 3. The drive for this gear comprises the power shaft 6 journaled inV an elongated bearing 20 in the base 19 and carrying at its upper end a gear 24 (Figs. 2 and 4) meshing with the gear 23 and provided at its lower end, which projects below the base 19, with a pulley 65. To steady the powe` shaft, I provide a pin 27 fastened at one end to the casing 18 and having its opposite end fit into a recess at the upper end of the shaft. The rollers 3, which are preferably three in number, are rotatably'mounted on spindles 25 Vsupported in bearings 26 on the ends of the arms 5, which latter are journaled on vertical pins 28, preferably' fixed at their endsV to the base 19 and casing18. In order` that the rollers 3 may at all times be driven from the gear 23, thel lowers endsof their` spindles are provided with gears 29 meshing with gears 30 rotatable on the pins 28 and arranged below the `arms 5. The pins 28 are spaced equidistantly from the central l stud 13 and 120O apart, and, of course, the same is true of the rollers 3, the arms 26 being of equal length. This arrangement provides for the automatic centering of the wheel on its support when the rollers are swung inwardly against the wheel vpreviously placed on the support.

Provision has to be made for easily and simultaneously swinging the rollers 3 into engagement with a wheel placed on the support 1 and toV this end I provide the arms 5 with segmental racks 31 (Fig. 2) meshing with a gear 32 rotatably mounted on the central stud 13 and sleeve 15. tating this gear 32 isV provided, which may comprise a hand lever 33 rigidly connected to the gear and extending through a slot 14 in the side of the casing where it can be readily grasped by the operator. is moved in a'direction to bring the rollers to 'their inoperative position, preferably by means of a spring 34. From this construction it will be seen that the rotation of the gear 32 will rock all the arms 5 simulaneously through the segmental rack 31 and to allow of such rocking movement the top of the casing is provided with arcuate slots where the bearings 26 extend therethrough. These slots may be covered by dust and grit excluding plates 67 (shown only in Fig. 3) connected to the bearings 26 and movable therewith.

To prevent wearing away or otherwise marring the lface of the wheel being trimmed, the rollers 3 are preferably provided with rims 35 of some soft metal or alloy, such as Babbitt metal. It is also d esirable to avoid excessive throw of the lever 33 to provide sets of rollers of different sizes for different sized wheels, and to" this end the rollers are made readily removable from their spindles, being splined to their shafts to prevent rotary movement, but al-` lowing endwise movement.

0n. a standard 39 bolted to the base 19 is mounted the cutting tool 8 and the means for adjusting it to its work. To provide for the vertical movement of the cutting tool this standard has slideways 40 bolted or ot ierwise fastened to its opposite sides. The support 9 for the cutting tool is slidably mounted on these ways and is provided with adjustable bearing blocks 41 which engage the ways, whereby they tighten or loosen the sliding iit between these members, as may be desired. This support or slide 9 has fastened to it an upwardly extending bar 42 which extends through and some distance above the bearing 43 at the upper end yof the Means for ro-Y The lever l tois 'formedy on this bar and the pinion 12 the wheel after the hand wheel is released by the operator after each cutting'operation, thus allowing the ready removal of the wheel and the placing of an untrimmed wheel in its place.

To allow the cutter to swing about the4 axis of the bar 42, a tubular member 46 is journaled on the bar and is held in position between the support 9 and a collar 47 fastened to the bar. To bring about this angui lar adjustment and to hold the vtubular member inits adjusted position, the slide 9 is formed with opposing lugs 48 which are provided with set screws 49 engaging the said tubular member.

To provide for the adjustment of the cutting tool at right angles to the wheel axis, I provide the head 50 in which it is 'mounted with a stem 51. This stem telescopically engages the tubular member 46 and is held in position by a set screw 52. Further means for adjusting the position or" the cutter are provided by having opposing lugs 53 lon the tubular member which are provided with set yscrews 54 engaging opposite sides of aprojection 55 rigid with the stem. The cutting tool bar 56, on the end of which the cutting tool is rotatably mounted, (Fig. 7) telescopes into a nut 57 and is held rigidly in place as by a screw 58. This nut engages a threaded opening 60 in the head,l which opening is slightly inclined to the vertical to give the cutting tool the proper cutting angle and by rotating this nut I am enabled to obtain a line up and down adjustment of the cutting tool. The nut is held in adjusted position by means of a set screw 61 (Fig. 2).

These various adjustments permit of setting the cutting tool with great precision to the particular work at hand.

To limit the downward movement of the may be held in adjusted position as .by

means or a screw 63 extending through a slot 66 in the stop member into the slideway 40 and so clamping the former against the latter. Without this stop the limit of the downward movement of the slide is determined by the force the operator applies to the hand wheel and thus the bushings of wheels oi a given thickness may be trimmed unevenly and the cutting tool dug into the wheel, particularly when the machine happens to be operated by an inexperienced operator. With the stop set for a given thickness of wheel, the cutter cannot be lowered beyond that point and all the wheels of that thickness will therefore be evenly trimmed,

cvenin thev hands of an inexperienced operator. The adjustment of the nut 57 in which the cutting Vtool is mounted may serve as a tine adjustment for setting the latter more accurately to its work after the adjustable stop '62 has been set and also to take care of the wear of the cutter without readjusting the stop 62. V

In operation, the device is supported at a Vconvenient height from the floor and-the power shaft is driven by any suitable means.` The operator places the wheel to be trimmed on the turntable 1 between the rollers 3, the rollers being in their outward position and in this position permitting the placing in position of wheels of' different sizes. The wheel being positioned, he grasps hand lever 33 with one hand and by the operation or this lever he swings the rapidly rotating v rollers inwardly against the periphery or-A the wheel, thus centering it on the support and lrotating it by the frictional drive ot the rollers on the wheel periphery. The cutting tool 8, if it has not previously been adjusted, is now adjusted by means of the various adjustments above described, so as to neatly and accurately trim the bushing, and the operator, with his other hand,then brings it into operative position to effect this trimming by rotating the hand wheel 10. As soon as the bushing is trimmed 0nV one side ci the wheel, which takes but a moment, the hand wheel 10 and lever 33 are released and the parts are returned to their initial position by the springs 34 and 44.- The operator then turns the wheel and re; peats the operation on the other side ofthe wheel. ,v f

yIt will be seen that by the use of my device I am enabled to eiciently and neatly trim the lead bushings "of grinding wheels in a minimum of time and with a consequent increase in production, and while I have explained my invention with reference to a machine having the precise details of construction shown and described, it should be understood that this is simply by way o'f illustration in order that the invention may be understood and that the various embodi-l ments are comprehended within the spirit and scope of the claims.

Having described the invention, what I claim as new and desire/to secure by Letters Patent or the United States is:

1. A wheel trimming machine comprising a cutting tool, a support for the same, and means :trictionall driving against and movable relative to t e surface of the wheel to rotate said ywheel while in engagement with the cutting tool. j I 2. A wheel trimming machine comprising a cutting tool, a support for the same to hold it in operative position relative to the wheel, and means for supporting and rotating the wheel comprising a driving roller rotated against the surface of said wheel.

3. A wheel trimming machine comprising a cutting tool, a support therefor and a roller adapted to drive against the periphery of the wheel while the cutting tool is held in operative engagement therewith.

41:. A wheel trimming machine comprising a cutting tool, a support for the same to hold it in operative position relative to the wheel, a support'for the wheel, a roller adapted to frictionally' drive against the surface of the wheel and means for relatively moving the wheel and roller into driving engagement. 5. A Wheel trimming machine comprising a cutting tool, a support therefor to hold it in operative position relative to the wheel, means to rotate the wheel comprising driving rollers adjustable relative to the wheel and means to move said rollers into driving engagement with the periphery of the wheel.

6. A wheel trimming machine comprising a cutting ltool, a support for the same, means adapted tor adjustably position the cutting tool relative to the wheel and means frictionally driving against and movable relative Y to the surface of said wheel to vrotate it.

7. A wheel trimming machine comprising a cutting tool, a support therefor, a substantially horizontal support for the wheel, a wheel driving roller, means for moving the wheel and roller into peripheral driving engagement, and means to relatively move the tool support and the Wheel support to bring the tool and wheel into operative engagement.

8. A wheel trimming machine comprising a wheel support, a wheel centering and rotating means comprising three or more rollers mounted on spindles, pivoted supporting arms for said spindles, means for simultaneously swinging said spindle supporting arms to cause the rollers to operatively engage a wheel placed on said wheel support, and means for driving one of said rollers in all positions of the same. y

9. A wheel trimming machine comprising a rotatable wheel support, driving rollers adapted'to engage the periphery of a wheel Yon said support, arms carrying said rollers and pivotally mounted for movement of the rollers toward and from the wheel axis, segy mental racksV rigidly connected to said arms andhaving their axes coinciding with the pivotal axes of the arms, a gear mounted to rotate about the axis of the Wheel support and meshing with said segmental racks and means for rotating Said gear. v

10. A wheel trimming machine comprising a rotatable wheel support, a driving roller adapted to engage the periphery of a wheel on said support, a pivotallymounted arm carrying said driving roller and permitting movement of the latterV relative to the wheel axis, a gear having its axis coinciding with thatof the roller and connected to drive the same, a second gear meshing `with the first-named gear having its axis coinciding with the pivot of said arm anda positively driven gear meshing with said second gear and having its axis coinciding with the wheel axis.

11. A wheel trimming machine comprising a cutting tool, a vertically slidable support therefor, a Ysubstantially horizontalgagement, a cutting tool and means for adl justing the cutting tool vertically and laterally to bring it into operative engagement with the wheel for trimming.

13. A wheel trimming machine comprising a turntable support for a wheel, a wheel driving means frictionally engaging and driving against the -periphery of the wheel,

a cutting tool, a support therefor slidable in a direction parallel to the wheel axis and a limit stop for said cutting tool support whereby the cutting tool cannot be lowered below the wheel side being trimmed.

14. A wheel trimming machine comprising a cutting tool, a support therefor, and an adjustable limit stop for the support and means on the support for coperating with the adjustable stop for makingv a precision adjustment of the tool to compensate for wear. l

Signed at VJorcester, Massachusetts, this 15th day of April, 1920.

THURE LARSSON. 

